Consumable product for ingot hot tops and the like



United States Patent Ofiice 3,352,743 Patented Nov. 14, 1967 York No Drawing. Filed Nov. 9, 1964, Ser. No. 419,019

12 Claims. (Cl. 161-162} This invention relates to consumable products for use with ingot and the like molds in the pouring and casting of metal ingots and molded shapes or items, and the method of producing the same. More specificaly this ininvention is directed to composition and constructions for consumable, refractory and insulating bodies or materials for the manufacture or fabrication of hot tops, sideboards and the like common products or aids for use with ingot and the like molds for the pouring and casting of metals.

A variety of constructions and compositions, including the so-called exothermic or neutral consumable materials or formulations, have been proposed and disclosed in the art for the manufacture or fabrication of hot tops, riser sleeves, insertable sideboards or slabs, and the like implemental products or components employed to facilitate and pouring of molten metal and casting or molding of ingots and forms. The functions of such hot tops, riser sleeves, sideboards etc., are of course familiar to the art. Briefly, these products or components comprise means of overcoming or retarding the formation of internal voids or cavities, commonly called pipes and fissures, within the cast metal ingot or body as a result of the preliminary or initial solidification of the outer or peripheral surface(s) of the poured ingot or mass coupled with the appreciable shinkage of the metal during the subsequent interinal solidification or uneven cooling and entrapped gases, and/or means of decreasing the depth to which such resulting structural defects progress or extended into ingot body or cast article. Hot tops, Sideboards, riser sleeves and the like ingot or metal casting aids or implementations in general or primarily achieve or produce these efiects by forming or providing a sinkhead or feederhead position on top, or just within the opening or mouth of the ingot or other mold which maintains or provides for an overlaying pool or reservoir of the molten metal to continuously feed the ingot or molded body during its solidification, supplanting or compensating for the appreciable internal shrinkage of the metal normally encountered and thereby reducing the extent or depth of the internal shrinkage cavity, and in turn the amount of metal subsequently wasted in cropping 013? this unsound portion of the ingot or cast body. Additionally, many of these constructions or products provide varying degrees of insulation to delay the cooling and solidification of their molten contents and thus extend the period of uninterrupted feeding of the liquid metal to the internal section of the cooling and shrinking ingot body.

Hot tops comprise the more common steel ingot casting aid, and the type most frequently or generally employed in the steel industry are formed or constructed either of clay, or of a refractory lined metal casing consisting of a plate or cast iron housing structure lined with refractory material or brick which in turn is typically coated or covered on the surface exposed to the molten metal with an expendable material which is replaced upon each use. Although economical in material costs, clay hot tops are heavy and frangible thereby entailing relatively high handling and breakage costs. More objectionable handicaps to clay hot tops are their relatively low steel yields and their removal or disposal from the ingot with the nuisance and/or hazard created by the inevitable clay fragments thereof on the floor of working areas, soaking pits, etc. The refractory lined metal casing type of hot top, in addition to requiring a substantinl initial or capital outlay, requires costly maintenance and handling due to the necessity of replacing its expendable inner lining upon each use, and its appreciable weight in transporting, installation and removal, etc. These, among other apparent deficiencies or costs encountered With such standard types of hot tops and related ingot aids have motivated the art to find or produce constructions or materials overcoming or improving upon the inadequacies of the prior products or means, with the result that a great number of compositions and/ or structures have been proposed, and more recently a particular class of such products of the so-called exothermic type wherein a component or components thereof of high heat or combustion, for example, aluminum and an ox gen source such as oxides of iron or manganese, are ignited by the heat of the introduced molten metal and burned as in a typical thermite reaction to supply heat to maintain the molten condition of the metal Within the hot top or adjacent to the sideboard inserts facilitating its function of providing a continuing molten reservoir to supplant the shrinking solidifying metal Within the ingot mold. Nevertheless, as yet these innovations have not been widely or extensively accepted and utilized in the steel and related industries for one reason or another. A primary obstacle presumably is costs whereby the extra expense of these products, particularly those incorporating relatively costly ingredients such as aluminum, etc., is not offset by a commensurate savings in additional steel yields or other metals recovered. Moreover, the ingredients and/ or the active combustion of the exothermic type of product frequently induces boiling in the molten metal, and/ or the introduction and dispersion of foreign materials or impurities and gases which constitute both a potential hazard to personnel and debase the soundness or quality of the steel or the other metal.

It is a primary object of this invention to provide a construction and/or composition for the formation or fabrication of hot tops, sideboard inserts, riser sleeves and the like ingot casting or molding aids for implementations which is low in material, construction and handling costs, and appreciably increases steel yields at significantly lower steel usage without introducing or facilitatmg the introduction or dispersion of impurities, physical defects or other degrading properties.

It is also an object of this invention to provide consumable, composite products of relatively light weight and yet high strength, or economical handling properties, and of low cost nonexothermic type materials or ingredients which provide an effective and highly efficient insulation appreciably prolonging the liquid state of the molten steel or metal adjacent thereto or Within its confines, thereby extending the time in which the molten metal overlaying or in the upper portion of the ingot will feed or flow downwardly into the body of the solidifying and in turn shrinking ingot minimizing the degree of depthof the pipe or shrinkage cavity and as a result thereof the amount of unsound steel or metal which must subsequently be cropped from the top of the ingot, thus increasing the steel yield with lower steel usage, in amounts of up to about 5 to 8% over conventional products.

It is further an object of this invention to provide consumable, composite products of a construction and composition that will resist disintegration or thermal decomposition from radiant heat or the like exposure to high temperatures prior to physical contact with molten steel or other metals whereupon the insulating backing component or section disintegrates through a slow retarded punking or smoldering action rather than flaming and is 3. and odor producing or leaving a residue of friable insulating ash which, coupled with the refractory lining component, insulates the contained molten metal for an extended period prolonging its solidification While at the same time confining and retaining the molten metal until a self-containing shell of solidified metal is formed, and which thereafterparts readily from the ingot or solidified metal surface and then is easily removed or disintegrated by a light jarring blow or shaking.

It is also a further object of this invention to provide a consumable, composite product which is self-supporting and possesses adequate mechanical strength and rigidity, without reinforcement or support, and durability to contain and resist a body of molten steel or othermetal and is of such coherency and flexibility to resist breakage when subjected to the normally rough or rigorous handling encountered in steel mills and foundries and to permit the wedging or driving of sections thereof into the opening or mouth of ingots and the like imolds, or the hanging or supporting of sections thereof by conventional means within the opening or mouth of such molds.

It is a still further object of this invention to provide consumable products composed of materials. or ingredients which in either their initial or consumed state, do not adulterate or contribute to the formation and/or introduction of impurities or adulterants and gases into the molten or solidifying metal and are of a degree of permeability as to readily permit and facilitate the evolution of gases and their dissipation or venting without inducing bubbling, boiling, churning or the like agitating actions in the molten steel or metal which carry down and disperse bodies of gases and/or impurities into and through the ingot mass and cause unsound steel or metal, and comprise. a hazard to personnel.

It is a still further object of this invention to provide a consumable product of a simplified construction and easy workability which enables and facilitates the fabrication or manufacture of hot tops, sideboard inserts, riser sleeves and the like metal casting or molding aids or implementation and in turn is amenable to adjustment or fitting to the ingot mold and to common fittings or securing means and techniques etc.

These and other advantages of this invention will be more apparent from the hereinafter detailed description.

This invention essentially consists of a novel and specific combination and construction composed or formulated of given components or materials, or classes thereof, which are so united or combined both in proportion or ratios with respect to the ingredients and in physical relationship or orientation of distinct bodies or masses of the particular combinations of certain of the respective ingredients whereby the overall co-action or cooperative effect of the ingredients and their arrangement provides a composite product possessing and effecting the foregoing useful and advantageous properties and characteristics, among others, and as such is especially adaptable to uses comprising the containment and insulation of molten metal and is amenable to the construction or fabrication of ingot hot tops, sideboard inserts, riser sleeves. and the like constructions or articles of conventional physical designs or configurations for these applications.

More specifically this invention consists of a product which in general is thermally consumable, refractory in part and an effective insulation for use with ingot molds, etc. in the pouring and casting of metal ingots or bodies and basically consists or is constructed of a relatively permeable composite integrated body comprising a refractory liner section or phase juxtaposely or contiguously physically united or joined to an insulating backing section or phase in a substantially contenminous. superim posed relationship.

The refractory liner layer component or section and.

facing of the product of this invention which is in direct contact with the molten metal must be of an effective thickness of at least about but preferably about A to about 1 inch in thickness and may range up to about 1 /2 inches or greater, and the mass thereof should be formed in an apparent or overall density for this section within the approximate range of about to about 130 lbs./cu. ft. with the optimum apparent density being about to about lbs/cu. ft; The composition of this component or face section of the composite product essentially consists of, by weight of this section of the product, approximately 80% to approximately 96% of sized granules of at least one alkaline earth metal carbonate of the group comprising calcium carbonate, magnesium carbonate, and dolomite, or blends of any combination or proportions of carbonates of this group, approximately 2% to approximately 8% by weight of organic resin, approximately 1% to approximately 4% by weight of starch,

and approximately 1% to approximately 6% by weight of relatively refractory or high temperature resistant inorganic binder such as sodium silicate, potassium silicate, aluminum phosphate, colloidal silica, colloidal alumina, colloidal zirconia, or clay, with the more economical sodium silicate or clay binders being preferred. Optimum properties for most applications are obtained with a formulation,.and therefore the preferred composition, comprising about 91.5% of dolomite or an approximately equivalent blend of calcium and magnesium carbonates, about 4% by weight of organic thermosetting resin such as a phenol formaldehyde resin, about 2% by weight of ordinary starch, and about 2.5% by weight of sodium silicate solids such as N Brand Soda, or No. 9 sodium silicate a product of Philadelphia Quartz.

To provide the necessary degree of porosity or permeability in this face section of the product to disperse and dissipate combustion and the like gases and yet retard penetration of the molten metal therein, the particle or grain size of the alkali earth metal carbonate should be a majority and preferably, substantially all within an. approximate range of about 6' mesh to about 35 mesh, Tyler Standard Screen Scale, or in the US. Sieve Series about 3.36 mm. to about 420 microns. A more specific and preferred particle size distribution comprises fractions having an approximate sieve analysis in the Tyler Standard Screen Scale of about all particles through 6 mesh, a maximum of about 15% of the particles retained on 10 mesh, a minimum of about 80% of the particles retained on 20 mesh and a minimum of about 96% of the particles retained on the 35 mesh.

A thermosetting or thermal curable phenol formaldehyde resin is preferably utilized because of its general availability and reliability, ease in applying and curing, and relatively high temperature resistance, among other desirable properties of such resins. However, substantially any other good bonding resin may suflice including, for example, urea formaldehyde, melamine formaldehyde, resorcinal formaldehyde, furanes, polyester, alkyds, epoxies, allyls, etc. The starch may comprise one produced from any of the usual vegetable sources as tapioca, potato, rice, corn, etc. which has been prepared in a conventional manner for use as an adhesive. The preferred inorganic binder, sodium silicate, comprises any of the usual commercially available grades of sodium silicate.

The insulating backing section or phase of this product likewise should be of adequate thickness to provide an effective insulation fulfilling the needs of the particular conditions of the application. The thickness of this component should be greater than about inch and generally at least about /2 to 1 inch and may extend up to 5 inches or greater with about a 2 to 3 inch thickness being adequate for most average or typical applications. The apparent density of this component of the product should be at least. about 18 lbs./ cu. ft. and preferbaly within the range of about 20 to 40 lbs/cu. ft. with the approximately 25 lbs./cu. ft. being optimum to effect the strength and handleability desired for constructing and installing ingot aids such as hot tops and sideboard inserts, and to provide good insulating properties and high residual ash content. The resulting ash of the heat expended or consumed component 0r section should be approximately 5 pounds of ash per cubic foot of the initial material or body of this section of the product; for example, with a 20 pound cubic foot material the minimum ash content would be about 25% by weight of the initial material and at a 25 lb./cu, ft. density of the approximate minimum ash content would be about 20%. The residual ash provides a continuing, effective insulation which is retained and endures upon combustion of the heat consumable ingredients of the initial insulating backing section and yet is readily removable by disintegration along with the refractory layer.

The ingredients of the insulating backing section, which together with the density of this phase of the product are responsible for the strength, insulating efiiciency, ash and other desirable properties of this component, essentially consist, in percent by weight of this section, of approximately 35% to approximately 70% by weight of wood fiber, to approximately 30% by weight of rice hulls but preferably and normally at least approximately to approximately 30% by weight of rice hulls, and approximately 20% to approximately 40% by Weight of clay. Although not essential to produce a satisfactory or useful product for many applications, appreciable amounts of rice hulls are highly desirable and typically included in the insulation backing sections to effect optimum control over and in general retard the rate of combustion or charring of this section and contribute to the body of the resulting ash, among other advanta es.

A preferred formulation for optimum properties under most typical circumstances comprises about 50% by weight of wood fiber, about 25% by weight of rice hulls, and about 25% by weight of clay. The wood fiber or pulp preferably comprises a rather coarsely ground soft wood but any source of cellulosic fiber can be included, for example kraft pulp, etc. The clay includes, but is not limited to, kaolin clay, cooley clay, M & D cla or any other of the common bonding clays.

When the given proportions or ratios of the said ingredients are combined into the composition of the respective components or sections and each in turn formed with the recited physical properties and united or joined and constructed as specified, a composite product or material is provided which is ignitible andconsumable upon direct physical exposure or contact with molten steel or like metal and upon completion of a slow or gradual relatively flameless charring or punking burn out of the combustibles therein, there remains a self sustaining friable body of ash which provides an effective continuing insulation which is easily disintegrated into a fine powder for removal and disposal. Moreover the specific composition(s) and construction produces a porous, slow charring or burning insulating product which by itself, or without support or reinforcement, retains and endures molten metal until a self-containing shell of solidified metal is formed and thereafter provides a highly effective insulation in all stages from its initial or unburnt state through to and including the resulting residual ash structure or body. And, the high permeability of this product at all stages enables and facilitates the dissipation of any gaseous products of the combustion thereby minimizing boiling or churning of the molten metal which furthers the distribution of any contained gases and/ or impurities therethrough the metal and comprises a hazard to personnel.

The insulating backer board component or section of this product is produced by dispersing the ingredients thereof in an aqueous medium and collecting, forming and consolidating the solids thereof into a board like article or layer by filtration or drainage utilizing any of the conventional means or techniques comprising Fourdrinier or Oliver type machines, a simple filter press, or the like common paper or board forming machines or apparatus. And although other forming techniques can be employed, because of the relatively thin sections normally utilized, it is preferred that the refractory liner layer be formed by casting a layer of apt or designed thickness of a wet or moist moldable mixture of components of this section or phase of the product admixed with water directly on one surface of a previously formed insulating backing board section as by spreading a wet or moist flowable or plastic mass thereof substantially uniformly over the insulating backing board, preferably employing an intermediate adhesive, followed by drying and curing of the resin contents thereof whereupon the manufacture of the product is complete. Resin curing temperatures and conditions are conventional and should be as given or required for the particular resin composition and product. The temperatures and conditions for the various resins or products thereof are available in the literature or from the vender. For example, a temperature of about 250 to 275 P. will effectively dry and cure many common phenol formaldehyde resins.

To facilitate bonding and effectively uniting or joining the sections of the two phases or components of this product a thin layer of water-compatible adhesive or bond ing agent can be spread over the surface of the insulating backing section prior to the application of the refractory liner material. Suitable adhesives comprise starch, animal glue, sodium silicate, synthetic adhesives, or the like which will resist separation of the components upon subsequent separation of the components upon subsequent cutting and fabrication of an ingot aid, insertion or application thereof to the ingot, and upon its exposure to the molten metal.

Because of obvious difficulties encountered in attempting to form a relatively thick product or layer of the component comprising the insulating backing board section, when it is desired or required to provide a product comprising the insulating backing board section of substantial thickness it is expedient to achieve or provide such thicknesses by laminating several layers or segments of the material to obtain the designed thickness. This may be readily accomplished by securing and laminating two or more layers or segments together with a conventional adhesive such as employed in adhering and bonding the insulating backing section or phase to the refractory liner section or phase of the composite product.

The following comprise specific illustrations or examples of preferred and typical compositions and/or constructions, and means of producing the same, for the novel products of this invention, and demonstrate physical properties of these novel products and the pronounced advantages and utility thereof. It is to be understood, however, that the specific formulations and/or constructions as well as the means described as employed in producing these products, or otherwise given hereinafter, are pri marily exemplary and are not to be construed as limiting the invention to any particular composition(s), construction(s), method(s), techniques(s), or condition(s) of these examples.

Example I Pursuant to the most expedient means contemplated for carrying out this invention or forming the product thereof, the insulating backer board section is first formed or produced and the refractory liner section applied and secured thereto. Products of this invention can thus be formulated and constructed pursuant to the following preferred procedures and means. The wood fiber containing insulating backing sections were produced in a conventional manner as in the common manufacture of wood fiber building and insulating boards in a typical Fourdrinier wet process machine, from an aqueous suspension comprising a solids. stock of about:

Ingredients: Percentages Ground wood pulp (pine) 43.0 Clay (kaolin) 35.5 Rice hulls 21.5

This stock formulated with about a 50% excess of clay to compensate for process losses in the machine formation and is designed to result in a finished product composition of approximately:

This component or phase of the product was continuously produced on the Fourdrinier in slab or board form in thicknesses of approximately /2 inch, cut to handleable segments, dried to a moisture content of about 1.5% or a maximum of about 4%, and segments thereof superimposed and laminated to each other with glue to achieve the desired thickness which in the instant case consisted of 6 layers to provide a total thickness of about 3 inches for the ultimate fabrication of insulating ingot sideboard inserts whereupon the thus formed sections of laminated segments were trimmed to proper size. The resulting insulating board products exhibited a dry apparent or article density of about 25 lbs/cu. ft. and an ash content of about 28 to 30% by weight of the initial material.

The insulating backer board sections, cut to proper size, were coated on one side or face with an aqueous suspen sion of 26% solids of starch adhesive applied to provide a coverage of approximately 0.1 lb./ sq. ft. and, individual sections thereof placed in a mold or form comprising retaining side walls for the application to the adhesive covered surface of the refractory liner component. The refractory liner composition comprised a damp to slightly wet plastic admixture of water and:

Ingredients: Percentages Dolomite 1 91.6 Phenol formaldehyde resin 2 4.2 Starch slurry (26% starch solids) 1.8 Sodium silicate (N brand) 2.4

1 Sieve analysis for the dolomite fractions within the following limits:

6 mesh 10 mesh maximum. mesh 80% minimum. 35 mesh 96% minimum. Catalin .No. 194 phenolic resin, Catalin Corporation of America.

The plastic mix comprising the refractory liner component was spread substantially evenly over the insulating backer board section to a thickness of about V to inch greater, to allow for shrinkage and compression than the intended or. designed final refractory liner section thickness which in the present case was about inch. This material was compressed and smoothed with a roller which pushed off excesses whereupon the backer board section and the refractory liner material were removed from the mold, dried and the resin content thereof cured at a temperature approximately 250 F. for a period of about 15 hours, but depending upon the circulating conditions of the particular drying and curing oven.

The foregoing products were fabricated into consumable sideboard inserts for ingot molds measuring about 15 inches in height and 62.5 or 52% inches in length, and essentially comprised a pair of insulating slab or boardlike bodies for use in large rectangular or elongated ingot molds whereby each is inserted and mounted or hung within and/ or adjacent the upper opening or mouth of the ingot mold with a board positioned against each longitudinal side of the mold whereby they prolong the molten state of the metal in the adjacent area in the upper portion or overlaying the balance of the ingot enabling the upper most portion of the body of metal to remain fluid to flow and fill the shrinkage cavity which forms as the balance of the ingot content cools. When so employed with conventional ingot molds in several steel mill production lines under routine conditions, the consumable sideboard inserts of the above composition and construction produced steel yields of from 82.6 up to 85.7% Whereas comparable sized but more costly exothermic sideboards produced yields of about 79.7% on the same heat, and the yields produced by clay hot tops were 75 to 78%. The

consumed sideboards of this invention were ultimately reduced to a friable ash which readily disintegrated and fell away as a granular powder upon conventional strip- 5 ping of the cast ingots from the molds.

Example II A similarly composed product comprising an insulating backer board manufactured on an Oliver filter type forming machine was produced from an aqueous suspension comprising a solids stock of:

Ingredients: Percentages Ground wood pulp (pine) 53.4

Clay (kaolin) 33.3

15 Rice hulls 13.3

which was designed to product an end product composition of about:

Ingredients: Percentages 20 Ground wood pulp 60 Clay Rice hulls 15 dried, and the resin content thereof cured at approximate.

ly 250 F.

Upon cutting to a suitable size, commensurate to the diof four sides of a hot top to fit the same, hot tops were assembled from these products by positioning four approximately equal dimensioned rectangular boards or slabs thereof in a substantial square or rectangular arrangement or configuration approximating the contemplated ingot mold openings and the four sides or boards comprising the same secured into self-supporting units with steel bands, thus providing an open top and bottom container type construction for positioning either on the top or just within the opening or mouth of the ingot mold with the lower portions of the hot top construction extending just within the opening or mouth. These products demonstrated adequate strength to endure the compression of the clamping with a band and handling with a 1 conventional steel mill crane for transporting and positioning on or within the ingot molds and contact with the molten metal whereupon in use they were subsequently reduced to a self-retaining insulating body of ash which readily disintegrated and fell away as dust-like granules upon stripping the molds.

As used throughout this specification and the appended claims, the term apparent density is intended and should be understood to mean and define the density of the product or article, or a segment thereof, as such, or in other words the density of the composition constituting the product or article including the volume thereof the surface and internal voids and interstices, or air or other gases entrained therein, and not the actual density of included solids components of the mass or average of the densities of each constituent forming the same in its relative proportions.

It will be understood that the foregoing details are given for purposes of illustration and not restriction, and that variations within the scope of this invention are to be included within the scope of the appended claims.

What We claim is:

1. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body com- 75 posed of a refractory liner section of at least about V8 mensions of the opening of the contemplated ingot molds inch in thickness and having an apparent density of about 80 to about 130 lbs/cu. ft. juxtaposed and united to an insulating backing section of at least about 4 inch in thickness and having an apparent density of greater than about 18 lbs/cu. ft.; said refractory liner section consisting essentially of approximately 80% to approximately 96% by weight of granules of at least one alkaline earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate and dolomite, approximately 2% to approximately 8% by weight of organic resin, approximately 1% to approximately 4% by weight of starch, and approximately 1% to approximately 6% by weight of inorganic binder; and, said insulating backing section consisting essentially of approximately 35% to approximately 70% by weight of wood fiber, to approximately 30% by weight of rice hulls, and approximately 40% by weight of clay.

2. The consumable refractory and insulating product of claim 1, wherein the granules of alkaline earth metal carbonate are sized with a majority of the particles within the approximate range of 6 mesh to 35 mesh.

3. The consumable refractory and insulating product of claim 2, wherein the insulating backing section has an ash content of at least about pounds of ash per cubic foot of the insulating backing layer material.

4. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body composed of a refractory liner section of at least about inch in thickness and having an apparent density of about 80 to about 130 lbs/cu. ft. juxtaposely united to an in-v sulating backing section of at least about /2 inch in thickness and having an apparent density of at least about 20 lbs./ cu. ft.; said refractory liner section consisting essentially of approximately 80% to approximately 96% by weight of granules of at least one alkaline earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate and dolomite, approximately 2% to approximately 8% by weight of organic resin, approximately 1% to approximately 4% by weight of starch, and approximately 1% to approximately 6% by weight of sodium silicate; and, said insulating backing section consisting essentially of approximately 35% to approximately 70% by weight of wood fiber, approximately 5% to approximately 30% by weight of rice hulls, and approximately 20% to approximately 40% by weight of clay.

5. The consumable refractory and insulating product of claim 4, wherein the granules of alkaline earth metal carbonate are sized with the majority of the particles within the proximate range of 6 mesh to 35 mesh.

6. The consumable refractory and insulating product of claim 5, wherein the insulating backing section has an ash content of at least about 5 pounds of ash per cubic foot of the insulating backing layer material.

7. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body composed of refractory liner section of about A to about 1.5 inches in thickness and having an apparent density of about 80 to about 130 lbs/cu. ft. juxtaposed and united to an insulating backing section of about /2 to about 5 inches in thickness and having an apparent density of about 18 to about 40 lbs./cu. ft.; said refractory liner section consisting essentially of approximately 80% to approximately 96% by weight of granules of at least one alkaline earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate and dolomite of particle sized a majority within the proximate range of 6 mesh to 35 mesh, approximately 2 to approximately 8% by Weight or organic resin, approximately 1% to approximately 4% by weight of starch, and approximately 1% to approximately 6% by weight of sodium silicate; and, said insulating backing section consisting essentially of approximately 35 to ap- '10 proximately 70% by weight of Wood fiber, approximately 5% to approximately 30% by weight of rice hulls, and approximately 20% toapproximately 40% by weight of clay.

8. The consumable refractory and insulating product of claim 7, wherein the insulating backing layer has an ash content of at least about 5 pounds of ash per cubic foot of the insulating backing material.

9. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body composed of a refractory liner section of about /2 to about 1 inch in thickness and having an apparent density of about 100 to 110 lbs/cu. ft. juxtaposed and united to an insulating backing section of about 1 inch to about 4 inches in thickness and having an apparent density of about 20 to about 40 lbs/cu. ft.; said refractory liner section consisting essentially of approximately to approximately 96% by weight of granules of at least one alkaline earth metal carbonate selected from the group consisting of calcium carbonate, magnesium carbonate and dolomite of particles sized a majority within the approximate range of 6 mesh to 35 mesh, approximately 2% to approximately 8% by weight of organic resin, approximately 1% to approximately 4% by weight of starch, and approximately 1% to approximately 6% by weight of at least one inorganic binder selected from the group consisting of sodium silicate and clay; and, said insulating backing section having an ash content of at least about 5 pounds of ash per cubic foot of board and consisting essentially of approximately 50% to approximately 60% by weight of wood fiber, approximately 15% to approximately 25% by weight of rice hulls, and approximately 20% to approximately 30% by weight of at least one bonding clay selected from the group consisting of kaolin clay, cooley clay, and M & D clay.

10. The consumable refractory and insulating product of claim 9, wherein the granular alkaline earth metal carbonate of the liner layer is of approximately particle size fractions having a sieve analysis of about all through 6 mesh, a maximum of about 15 retained on 10 mesh, a minimum of about 80% retained on 20 mesh, and a minimum of about 96% retained on 35 mesh.

11. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body composed of a porous refractory liner section of approximately /2 to approximately 1 inch in thickness and havng an apparent density of about to 100 lbs./ cu. ft. uxtaposed and united to an insulating backing section of approximately 1 inch to approximately 4 inches in thickness and having an apparent density of about 30 lbs/cu. ft. said refractory liner section consisting essentially of approximately 91.5% by weight of granular calcium and magnesium carbonate particle size substantially all within the approximate range of 6 mesh to 35 mesh together with approximately 4% by weight of phenolic resin, approximately 2% by weight of starch, and approximately 25% by weight of sodium silicate; and, said insulating backer section having an ash content of about 20 to 35 by weight of the original material and consisting esser1- trally of approximately 50% by weight of wood fiber, approxlmately 25% by weight of rice hulls, and approximately 25 by weight of kaolin clay.

12. A consumable refractory and insulating product for use with ingot molds in pouring and casting metal ingots comprising a permeable, composite integrated body composed of a porous refractory liner section of approximately /2 to approximately 1 inch in thickness and having an apparent density of about 100 lbs./cu. ft. juxtaposed and united to an insulating backing section of approximately 2 to 3 inches in thickness and having an apparent density of about 25 lbs./cu. ft.; said refractory liner section consisting essentially of approximately 91.5% by weight of granular calcium and magnesium carbonate particles of approximate particle size fraction having a sieve analysis of about all through 6 mesh, a maximum of about 16% retained on 10 mesh, a minimum of about 80% retained on 20 mesh, and minimum of about 96% retained on about 35 mesh, together with approximately 4% by weight of phenolic resin, approximately 2% by weight of starch, and approximately 2.5% by weight of sodium silicate; and, said insulating backing section having an ash content of about 28% by weight of the original material and consisting essentially of approximately 50% by weight of wood fiber, approximate- 12 ly 25% by weight of rice hulls and approximately 25% by weight of kaolin clay.

References Cited UNITED STATES PATENTS 3,281,308 10/1966 DAsto l6l-162 MORRIS SUSSMAN, Primal Examiner.

w. I. VANBALEN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,352,743 November 14, 1967 Walter George Pusch et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 27, for "and", first occurrence, read the line 37, for "terinal" read ternal line 39, for "extended" read extend column 4, line 69, strike out "the", second occurrence; column 9, line 17, for "proximately 40% by weight of clay" read proximately 20% to approximately 40% by weight of clay Signed and sealed this 15th day of April 1969.

SEAL) Lttest:

EDWARD J. BRENNER Commissioner of Patents dward M. Fletcher, Jr.

lttesting Officer 

1. A CONSUMABLE REFRACTORY AND INSULATING PRODUCT FOR USE WITH INGOT MOLDS IN POURING AND CASTING METAL INGOTS COMPRISING A PERMEABLE, COMPOSITE INTEGRATED BODY COMPOSED OF A REFRACTORY LINER SECTION OF AT LEAST ABOUT 1/8 INCH IN THICKNESS AND HAVING AN APPARENT DENSITY OF ABOUT 80 TO ABOUT 130 LBS./CU. FT. JUXTAPOSED AND UNITED TO AN INSULATING BACKING SECTION OF AT LEAST ABOUT 1/4 INCH IN THICKNESS AND HAVING AN APPARENT DENSITY OF GREATER THAN ABOUT 18 LBS./CU. FT.; SAID REFRACTORY LINER SECTION CONSISTING ESSENTIALLY OF APPROXIMATELY 80, TO APPROXIMATELY 96% BY WEIGHT OF GRANULES OF AT LEAST ONE ALKALINE EARTH METAL CARBONATE SELECTED FROM THE GROUP CONSISTING OF CALCIUM CARBONATE, MAGNESIUM CARBONATE AND DOLOMITE, APPROXIMATELY 2% TO APPROXIMATELY 8% BY WEIGHT OF ORGANIC RESIN, APPROXIMATELY 1% TO APPROXIMATELY 4% BY WEIGHT OF STARCH, AND APPROXIMATELY 1% TO APPROXIMATELY 6% BY WEIGHT OF INORGANIC BINDER; AND, SAID INSULATING BACKING SECTION CONSISTING ESSENTIALLY OF APPROXIMATELY 35% TO APPROXIMATELY 70% BY WEIGHT OF WOOD FIBER, 0 TO APPROXIMATELY 30% BY WEIGHT OF RICE HULLS, AND APPROXIMATELY 40% BY WEIGHT OF CLAY. 